R33 Rb30 Conversion

[dnb]

im going to tee the oil return to the turbo oil return pipe.

i cant remember exactly(and im on the piss!)(merry christmas!) but the blocks are different at the oil filter.just run the filter without the cooler rb30 style.

[dnb]

my cam covers dont have the lumps at the back. whats the go there? it has vct but no lumps??????????

[RB30-POWER]

Its a series II that i am stripping if that makes a difference with regards to the cam covers?

[RB30-POWER]

Ok, stripped my RB25DET motor today to start the conversion.

I found the oil cooler will basically bolt straight up to the RB30 block without drama, the rb30 will have the extra filter bypass valve, but that shouldn't matter. Should function as normal.

The Series II RB25DET oil pump will bolt straight up to the rb30 crank without drama.

(It must be only the r33 gtr and up that has a larger oil pump?)

I think i will get the VCT gallery welded up in the head.

If i use a bung it may crack due to the thermal expansion rates of the head and bung?

And would anyone like to confirm where and how much weld they built up on the rb25 head water gallery for better clamping in the below picture, please?

Cheers

Mick

[dnb]

just get a 3l gasket and put it on. you will see what you need then

[dnb]

by the way that head looks very oily. the engine must have been stuffed. id be getting some new valve stem seals if i were you

[Cubes]

I found the oil cooler will basically bolt straight up to the RB30 block without drama, the rb30 will have the extra filter bypass valve, but that shouldn't matter. Should function as normal.

Ask some one who knows for sure.

Darren was unsuccessful with his attempt to run 2 bypass valves.

The Series II RB25DET oil pump will bolt straight up to the rb30 crank without drama.

(It must be only the r33 gtr and up that has a larger oil pump?)

The Series 2 and maybe some series 1.5 R33 GTST's had the better oil pump/crank collar.

[RB30-POWER]

Ok, so there might be a problem with the oil cooler then...

What problems was he having? I was looking at it all and couldnt see why the rb30 valve would make a difference, it should only bypass oil, if the filter causes a restriction.

The oil cooler connects to the block just as an ordinary filter would and should operate just the same as a standard filter, regardless of the extra bypasses in the cooler itself?

Well then if that is a problem, if i bunged the rb30 bypass up with a grub screw it would function exactly as the RB25 would, correct?

The oil pump i removed had a wider collar for the crank drive than the RB30 pump had.

But the RB25 crank drive was identical in all specs to the RB30.

With regards to the oil stuff in the cylinder.

The motor had done approx 40,000 when i got it the other day. It was a complete running rb25det. No oil in the inlet manifold and i dont think the valve stems would be stuffed on every cylinder on a low k motor to allow oil in. I think its fuel as it wipes off easy as?

[the phantom]

There is no need to weld up the VCT gallery...just thread it and use a grub screw. The head is littered with metal grub screws everywhere anyway from the factory.

I didn't do any welding of the water gallery. I actually trimmed the RB30 head gasket to match the head, and used a die grinder to open up the block side to mach as well as possible. There was probably about 5mm of material available for clamping in this area left, and I figured it's only got about 1 bar of water pressure to hold. Seemed to work fine for me. Has anyone else done this, or does everyone do the welding?

I removed the Rb30 oil bypass thing to ensure proper block cleaning, and just made a plug to block it off later.

My RB30DET is now officially dead. Following a recent turbo failure, the radiator top tank exploded on a recent hot day. With all the water gone the temp gauge showed normal and I didn't realise anything was wrong until the motor severely overheated and seized. I waited for it to cool and managed to start it and drove it to work. Upon repair and refit of the radiator it never sounded ok with missfires and overheating was indicated by my powerFC hand controller. I'd say its probably a blown head gasket or cracked head leaking water into the chambers as there is no water in the oil. I also didn't see the guage respond to match the temperature the FC was showing...it still showed normal...again!! Something people might want to check for peace of mind. I'll keep everyone posted on what I find.

As for the turbo failure, I'm wondering if improper water cooling led to the failure. Perhaps the thermal syphoning of the water was not functioning correctly as a result of the custom lines. This is something discopotato mentioned somewhere that got me thinking.

I have to admit, I've taken for granted how good skylines are in having to drive various other cars in the interim. Its not only the power, but the dynamics of handling and steering...hard to beat in my opinion.....

[Bl4cK32]

ive noticed that too on mine phantom. The temp gauge does stay about 3/4 when the temp gets right up. People might want to replace the sensor when upgrading the motor, or use an aftermarket water temp gauge.

sorry to hear its gone, but i bet you're looking forward to the new motor though

I do know how u feel about driving other cars in the interim though....

[Alf]

The temp gauge does stay about 3/4 when the temp gets right up.

Are you guys experiencing cooling problems with the factory cooling system?.

I'll might put the cams aside for now and get a custom alloy radiator and mandrel bent alloy piping to replace the factory radiator hoses.

[Bl4cK32]

got a small coolant leak, so i need to sort it. It sits about 87 odd degrees all the time, but due to the big fmic i got, and weather (read 38 degree day) it went up into the 90's....no major problems though

[dnb]

just be wary of aluminium radiators,electrolosis can kill them in no time

i had a 5 row core put in my original end tanks.works bloody beautifully

[RB30-POWER]

Thanks for the info phantom.

Ill confirm with a head guru, see if they think the gallery is ok as is.

I have to get it re-surfaced anyway before i bolt it up.

As for the RB30 bypass valve, i grub screw that bugger as well.

Cheers

[discopotato03]

Hello Phantom and all , I went to some trouble to make sure that the hot water return line was up hill from the turbo to the cooling system before the thermostat . Please note that FJ20's have the thermostat in the top hose not the bottom one like RB's . It is often more convienent to have both water banjo's facing down on the turbo but it makes the turbo water jacket the high point and will not thermosyphon . Water boils into steam which wont keep the core temperature down and cannot escape. Did your turbo sieze or did it damage the wheels ?

I gather that most of these engines wind up in R32/33 Skylines so I guess the GTR intercooler / radiator placement in those cars should be optimal ? It seems that lots of people go to tremendous efforts to put huge FMIC's in front of radiators and lose cooling efficiency which affects reliability . I think Sydneykid did once mention how much power the GMS GTR's were making with a standardish ? intercooler . My prioritys are normal coolant temps which to me means around 80-85C then worry about intercooling capacity . This cooling problem tends to rear its ugly head with engine transplants ie RB's in S13's or FJ20's in Bluebirds as its very differend to what the factory did with its original models . Airflow is critical to cooling both air and water so if you can make it easy to get into and out of the engine bay you've got a fighting chance . The radiator I'll start out with is a Koyo R32 GTR item that measures 20mm core thickness , it only has a sing row of tubes and made a hell of a difference to the Bluebird which had elec fans and a large FMIC .

Cheers A .

[Cubes]

got a small coolant leak, so i need to sort it. It sits about 87 odd degrees all the time, but due to the big fmic i got, and weather (read 38 degree day) it went up into the 90's....no major problems though

Darren,

I am 99% sure you have an underlying problem with either the radiator or the clutch fan.

Mark the owner before you also had cooling issues, which is partially the reason why he sold it. I think he thought it had a stuffed head.

Coolish days was fine however on Hot days the coolant would always spew out the overflow a little, eventually running the system low on coolant, sucking in air then making the problem worse.

Get that Clutch attached to the fan checked out.

I've got a spare one that turns out it is bran-new from my sisters CL Commodore you can try.

99% sure thats you problem.

My FMIC is approx 100mm thick bar and plate. Even on the hottest days it never hits 90degree's.

This was not always the case as origionally I found the car would spew out a little coolant so I got the radiator cleaned/pressure tested and also had twin 12" thermo's fitted.

This actually made the problem worse. 35+degree days with the aircon on and the temp would slowly creep up and up until some where around 3/4.

Then coolant would spew out and eventually the temp would get damn close to the H.

Off I went to a mates g/friends old man who owns a mechanics workshop.

He spent around 40mins on it bleeding the head & doing the usual CO2 tests etc.

He said.. Piss off these thermo's they are not covering enough surface area to cool the coolant.

I put the shroud, fan & clutch back on but with a new second hand clutch.

100% perfect.

The temp guage never moves around more than around 1/2 a needle width and the coolant level never ever needs topping up.

Most importantly the engine overheat fan in front of the condensor now never turns on as the engine overheat fan is designed to turn on at around 90degree's.

[Alf]

There is one thing I cannot understand about the position of the thermostat on the RB, why the hell would it be postioned where the lower hose is connected. :confused:

Never seen any other engine like it.

Wouldn't it be better to remove the thermostat and place it inline with the top hose, in some sort of housing and do some rearranging of the water pipes etc..

[Fitzpatrick Speed Works]

it is in the lower hose to position it well below the radiator water line. To add some reverse engineering to understand the poroblem look at the vl commodore where the fill up point was lower than the highest point in the cooling system they always cracked head cause the bubbles in the cooling system would gather in the back of the head and crack them. PLus the way water criculats in the rb engine it is the last outlet so it is the stappoer that allows the water to heat up in the engine first!!

[Alf]

Which way does the water flow in a RB?, ie from radiator, through bottom hose into block etc...

[RB30-POWER]

Water flows in the lower hose from the radiator to the block and out of the top hose back into the radiator.

Ever felt the radiator hoses while the car is running, bottom one is cool and the top is hot.